Downing, who joined Villa from Middlesbrough in the summer, came off the bench against Burnley on Saturday.
The England winger has been out with a injury since last season.
O’Neill said: “I think that’s a big plus for him. In terms of match fitness, he’s a distance away but I thought a spurt here would be useful and he might provide something.
“He has got into the action, which is great, and he can only improve. We have a game in midweek he will play in. Just being part of it after that injury is great for him.”
